1. Field of the Invention
The present invention relates to an apparatus for, and a method of, recording data to a disc having formed thereon alternately a track of which both walls are wobbled at a predetermined frequency and a track of which both walls are flat, and an apparatus for, and a method of, reproducing data recorded on the disc.
2. Description of Related Art
Optical discs in which program data, video data, audio data or the like is recorded are represented by compact discs (CD), for example.
Recently, it is expected that a medium appears into which the user can record a program data, video data, audio data, etc.
Currently, a mini disc (MD) is known to which a compressed audio signal can be recorded. The MD has a recording capacity as small as 140 MB and so it is suitably usable for recording audio data. However, this recording capacity is insufficient for recording video data and computer data.
In these situations, an magneto-optical disc has newly been proposed which has a recording capacity of 640 MB. This new disc is called "MD-DATA2" disc.
In the conventional MD, grooves wobbled at a frequency of 22.05 kHz are pre-formed on the disc and an address information is recorded as modulated at 22.05 kHz.
In the newly proposed MD-DATA2 to which the present invention is applied, a wobbled groove and non-wobbled groove are formed alternately as shown in FIG. 1 and data is recorded on a land between the wobbled and non-wobbled grooves.
As shown in FIG. 2, there are formed on the MD-DATA2 disc a first land TrA of which one lateral face is wobbled at a predetermined frequency while the other lateral face is flat and a second land TrB of which one lateral face is flat while the other lateral face is wobbled at a predetermined frequency.
Namely, there has not ever been proposed any MD in which data is recorded on two tracks having different physical properties.